Ventricular fibrillation is always diagnosed in an emergency situation. If sudden cardiac death has occurred, a pulse check will reveal no pulse.

Tests to diagnose and determine the cause of ventricular fibrillation include:

  • Electrocardiogram (ECG or EKG). This quick and painless test measures the electrical activity of the heart. Sticky patches (electrodes) are placed on the chest and sometimes the arms and legs. Wires connect the electrodes to a computer, which displays the test results. An electrocardiogram (ECG) can show if the heart is beating too fast or too slowly. If you're having an episode of ventricular fibrillation, the ECG usually shows a heartbeat of about 300 to 400 beats a minute.
  • Blood tests. Blood tests can be done to check for proteins (enzymes) that leak into the bloodstream when the heart is damaged by a heart attack.
  • Chest X-ray. An X-ray image of the chest can show the size and shape of the heart and its blood vessels.
  • Echocardiogram. This noninvasive test uses sound waves to create images of the heart in motion. It can show the heart's size and structure.
  • Coronary catheterization (angiogram). This test helps health care providers see blockages in the heart arteries. A long, thin flexible tube (catheter) is inserted in a blood vessel, usually in the groin or wrist, and guided to the heart. Dye flows through the catheter to arteries in the heart. The dye helps the arteries show up more clearly on X-ray images and video.
  • Cardiac computerized tomography (CT). A computed tomography (CT) scan uses X-rays to create cross-sectional images of specific parts of your body.
  • Cardiac magnetic resonance imaging (MRI). This test uses a magnetic field and computer-generated radio waves to create detailed images of blood flow in the heart.


Ventricular fibrillation requires emergency medical treatment to prevent sudden cardiac death. The goal of emergency treatment is to restore blood flow as quickly as possible to prevent organ and brain damage.

Emergency treatment for ventricular fibrillation includes:

  • Cardiopulmonary resuscitation (CPR). cardiopulmonary resuscitation (CPR) mimics the pumping motion of the heart. It keeps blood flowing through the body. First call 911 or your local emergency number. Then start CPR by pushing hard and fast on the person's chest — about 100 to 120 compressions a minute. Let the chest rise completely between compressions. Continue CPR until an automated external defibrillator (AED) is available or emergency medical help arrives.
  • Defibrillation. This treatment is also called cardioversion. An automated external defibrillator (AED) delivers shocks through the chest wall to the heart. It can help restore a regular heart rhythm. As soon as an automated external defibrillator (AED) is available, apply it and follow the prompts. If you're not trained to use an AED, a 911 operator or another emergency medical operator may be able to give you instructions. Public-use automated external defibrillators (AEDs) are programmed to recognize ventricular fibrillation and send a shock only when needed.

Other treatments for ventricular fibrillation are given to prevent future episodes and reduce the risk of arrhythmia-related symptoms. Treatment for ventricular fibrillation includes medications, medical devices and surgery.


Drugs to control the heart rhythm (anti-arrhythmics) are used for emergency or long-term treatment of ventricular fibrillation. If you're at risk of ventricular fibrillation or sudden cardiac death, your provider may prescribe medications to slow and control your heartbeat.

Surgery or other procedures

Surgery or medical procedures to treat ventricular fibrillation include:

  • Implantable cardioverter-defibrillator (ICD). An implantable cardioverter-defibrillator (ICD) is a battery-powered unit that's implanted under the skin near the collarbone — similar to a pacemaker. The ICD continuously monitors the heart rhythm. If the device detects an episode of ventricular fibrillation, it sends shocks to stop it and reset the heart's rhythm.
  • Cardiac ablation. This procedure uses heat or cold energy to create tiny scars in the heart to block the irregular heart signals that cause ventricular fibrillation. It's most often done using thin, flexible tubes called catheters inserted through the veins or arteries. It may also be done during heart surgery.
  • Coronary angioplasty and stent placement. If ventricular fibrillation is caused by a heart attack, this procedure may reduce the risk of future episodes of ventricular fibrillation.

    The health care provider inserts a long, thin tube (catheter) through an artery, usually in the groin, to a blocked artery in the heart. A balloon on the tip of the catheter briefly inflates to widen the artery. This restores blood flow to the heart. A metal mesh stent may be placed into the artery to help it stay open.

  • Coronary bypass surgery. This open-heart surgery redirects blood around a section of a blocked or partially blocked artery in the heart. It may be done if ventricular fibrillation is caused by coronary artery disease. During bypass surgery, the surgeon takes a healthy blood vessel from the leg, arm or chest. It's connected below and above the blocked artery or arteries in the heart. This creates a new pathway for blood flow.

Clinical trials

Explore Mayo Clinic studies testing new treatments, interventions and tests as a means to prevent, detect, treat or manage this condition.

Self care

Lifestyle changes that help keep the heart as healthy as possible include the following:

  • Eat a healthy diet. Heart-healthy foods include fruits, vegetables and whole grains, as well as lean protein sources such as soy, beans, nuts, fish, skinless poultry and low-fat dairy products. Avoid added salt (sodium), added sugars and saturated fats.
  • Exercise. Physical activity helps you achieve and maintain a healthy weight. Regular exercise helps control diabetes, high cholesterol and high blood pressure — all risk factors for heart disease. With your provider's OK, aim for 30 to 60 minutes of physical activity most days of the week. Talk to your health care provider about the amount and type of exercise that's best for you.
  • Manage weight. Being overweight increases the risk of heart disease. Talk with your care provider to set realistic goals for body mass index (BMI) and weight.
  • Don't smoke. Smoking is a major risk factor for heart disease, especially atherosclerosis. Quitting is the best way to reduce the risk of heart disease and its complications. If you need help quitting, talk to your provider.
  • Manage blood pressure and cholesterol. Get regular health checkups to monitor blood pressure and cholesterol. Take medications as prescribed to manage high blood pressure or high cholesterol.
  • Limit alcohol. Too much alcohol can damage the heart. If you choose to drink alcohol, do so in moderation. For healthy adults, that means up to one drink a day for women and up to two drinks a day for men.
  • Get regular checkups. Take your medications as prescribed. Have regular follow-up appointments with your health care provider. Tell your provider if your symptoms worsen.
  • Practice good sleep habits. Poor sleep may increase the risk of heart disease and other chronic conditions. Adults should aim to get 7 to 9 hours of sleep daily. Kids often need more. Go to bed and wake at the same time every day, including on weekends. If you have trouble sleeping, talk to your provider about strategies that might help.

Coping and support

Some irregular heart rhythms (arrhythmias) can be triggered by emotional stress. Taking steps to ease stress and anxiety can help keep the heart healthy. Getting more exercise, practicing mindfulness and connecting with others in support groups are some ways to reduce and manage stress. If you have anxiety or depression, talk to your provider about strategies to help.

Some types of complementary and alternative therapies may help reduce stress, such as:

  • Yoga
  • Meditation
  • Relaxation or mindfulness techniques

Getting support from loved ones may also be helpful.

October 28, 2022

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